Search PubMed⌕ Search

Biomedical subjects

T Maeda

Publications and source records attributed to T Maeda.

At least 217 records · Page 12Linked to original sources

Effects of short-term pulmonary rehabilitation on exercise capacity and quality of life in patients with chronic obstructive pulmonary disease.

Although the rehabilitation of patients with chronic obstructive pulmonary disease (COPD) improves both exercise capacity and quality of life, a standard protocol for COPD patients has not been established. To clarify whether physiologic and quality-of-life improvements can be achieved by an inpatient pulmonary rehabilitation program 5 days per week for 3 weeks, 18 patients with COPD were enrolled in a rehabilitation program. The physical exercise training regimen consisted of respiratory muscle stretch gymnastics and cycle ergometer exercise training. Pulmonary function tests, an incremental ergometer exercise test, a 6-min walking test, and a quality of life assessment by the Chronic Respiratory Questionnaire were administered before and after the program. The peak VO2, an indicator of maximal exercise capacity, did not increase, although the 6-min walking distance, an indicator of functional exercise capacity, increased significantly after rehabilitation. There was a significant improvement in the quality of life in terms of dyspnea, fatigue, and emotional state. These findings suggest that even a 3-week program may be beneficial for COPD patients. Increases in functional exercise capacity, even without an increase in maximal exercise capacity, are helpful for reducing dyspnea and improving quality of life parameters in patients with COPD.

Aged↗

Tissue response to titanium implants in the rat maxilla: ultrastructural and histochemical observations of the bone-titanium interface.

BACKGROUND: The detailed mechanism of osseointegration, the most appropriate implant-bone interface, remains unclear in jaw tissues at the ultrastructural level in contrast to the many reports using long bones. The present study reports on tissue response to titanium-implantation on an animal model using rat maxilla. METHODS: Animals were sacrificed at 1 to 28 days post-implantation and prepared tissue specimens, freed from implants by a cryofracture technique, were processed for transmission electron microscopy and histochemistry for tartrate resistant acid phosphatase activity (TRAPase). RESULTS: Different patterns in bone formation were recognized between lateral and base areas of implant cavities. In the lateral area with narrow gaps, bone deposition took place from the pre-existing bone towards the implant after active bone resorption by osteoclasts reactive to TRAPase. However, no distinct bone formation appeared in the lateral area where the implant had been installed close to the osteotomy margin. On the other hand, new bone formation was found at the base area without any apparent bone resorption. Interestingly, mononuclear cells reactive to TRAPase, presumably preosteoclasts, frequently occurred near preosteoblasts. Osseointegration around the implants was obtained in this model by 28 days post-implantation except for the lateral area with complete contact with implants, where the thin layer remained in contact with the implant surface. CONCLUSIONS: These findings indicate that ossification proceeds at different modes around the titanium implant in rat maxilla, depending on the nature of the recipient bones and the dimension of the gap between the implant and osteotomy margin.

Animals↗

A histochemical investigation of the bone formation process by guided bone regeneration in rat jaws. Effect of PTFE membrane application periods on newly formed bone.

BACKGROUND: Guided bone regeneration (GBR) has been widely utilized for the promotion of bone augmentation in bone loss areas. However, little information has been available regarding chronological changes in newly formed bone and alterations in the nature of newly formed bone after removal of a barrier membrane. The present study attempted to establish a GBR model for rat maxillae. We also examined the effects of membrane application periods on newly formed bone and its remodeling process after removal of the membrane in this experimental model. METHODS: Thirty-five Wistar rats were divided into 2 groups: a membrane application group and a membrane removal group. The chronological changes of newly formed bone were evaluated histologically and statistically. RESULTS: At 2 weeks after the GBR procedure, bony cavities had completely filled the newly formed bone in the experimental side. In the control side, corticalization on the surface of the newly formed bone proceeded with a decrease in the bone marrow cavity, whereas the bone marrow space had enlarged by 12 weeks post-surgery in the experimental side. In the membrane removal group, the osteoblasts appeared on newly formed bone at 1 week after membrane removal. Comparatively thick compact bone had formed on the surface of the newly formed bone at 4 weeks after membrane removal, and corticalization proceeded later. CONCLUSIONS: The long-term application of a barrier membrane induces the enlargement of the bone marrow spaces. We suggest that PTFE membrane removal in adequate time promotes the corticalization and maturation of the newly formed bone by the GBR technique.

Acid Phosphatase↗

Cardiorespiratory responses during cycle ergometer exercise with different ramp slope increments in patients with chronic obstructive pulmonary disease.

OBJECTIVE: The ramp exercise test has been widely used to evaluate cardiopulmonary responses to an incremental exercise load. This study was performed to clarify whether different slopes of the ramp exercise test influence exercise tolerance, exercise limiting factors, and respiratory pattern in patients with chronic obstructive pulmonary disease (COPD). SUBJECTS AND METHODS: We applied three different slopes (5 W/min, 10 W/min and 20 W/min) of the ramp exercise test in 9 patients with COPD and evaluated cardiopulmonary responses. RESULTS: There were no significant differences in peak oxygen uptake, anaerobic threshold (AT), minute ventilation, heart rate, arterial oxygen saturation, expired tidal volume, or respiratory rate at the maximal load among the three different ramp exercises tested. AT could be determined in six of nine patients (67%) at the slope of 5 W/min, in 8/9 (89%) at the slope of 10 W/min, and in 9/9 (100%) at the slope of 20 W/min. CONCLUSION: The findings suggest that the ramp slope does not affect exercise tolerance, exercise limiting factors, or respiratory patterns and each of these ramp slopes is useful for the evaluation of COPD. Ramp slopes of 10 W/ min or 20 W/min should be appropriate for the determination of AT.

Aged↗

CT assessment of the inferior peripancreatic veins: clinical significance.

OBJECTIVE: The purpose of this study was to evaluate and clarify the clinical significance of CT scans of the inferior peripancreatic veins. MATERIALS AND METHODS: Forty-three patients with suspected pancreatic disease underwent three-phase helical CT (collimation, 5 mm; reconstruction, 2.5 mm; scan delay, 30, 60, and 150 sec). The frequency of visualization on CT of the anterior and posterior inferior pancreaticoduodenal veins, inferior pancreaticoduodenal vein, and first jejunal trunk was assessed and correlated with angiographic and pathologic findings. RESULTS: The frequency of visualization of normal inferior peripancreatic veins in patients (n = 22) with a normal portomesenteric vein was 36% for the anteroinferior pancreaticoduodenal vein, 36% for the posteroinferior pancreaticoduodenal vein, 59% for the inferior pancreaticoduodenal vein, and 100% for the first jejunal trunk. The smaller inferior peripancreatic veins were frequently not visualized when normal. In patients (n = 13) with pancreatic carcinoma involving the portosuperior mesenteric vein, all of the inferior peripancreatic veins were dilated and easily recognizable. When the tumor did not involve the portosuperior mesenteric vein but did involve the anteroinferior pancreaticoduodenal, posteroinferior pancreaticoduodenal, and inferior pancreaticoduodenal veins (n = 8), some of the other peripancreatic veins (first jejunal trunk, anterior and posterior superior pancreaticoduodenal veins, and gastrocolic trunk) were dilated. Dilatation indicated tumor extension to the third portion of the duodenum. In patients (n = 7) with involvement of the inferior pancreaticoduodenal vein, the first jejunal trunk, or both without the involvement of the portosuperior mesenteric vein, dilatation of the other peripancreatic veins (anteroinferior pancreaticoduodenal vein, posteroinferior pancreaticoduodenal vein, anterosuperior pancreaticoduodenal vein, posterosuperior pancreaticoduodenal vein, and gastrocolic trunk) indicated tumor invasion of only the second portion of the extrapancreatic nerve plexus (n = 4) and tumor invasion of both the second portion of the extrapancreatic nerve and the mesenteric root (n = 3). CONCLUSION: Dilatation of peripancreatic veins with nonvisualization of inferior peripancreatic veins suggests tumor invasion of peripancreatic tissue.

Adult↗

Biomechanical evaluation of foot pressure and loading force during gait in rheumatoid arthritic patients with and without foot orthosis.

Foot orthoses are commonly used in patients with rheumatoid arthritis (RA) to support the foot and relieve pain, however little is known about the biomechanical effects of in-shoe foot orthoses in reducing or redistributing high pressures and loading forces. The purpose of this study was to compare the foot pressures and loading forces during gait in rheumatoid arthritic patients and healthy subjects, and evaluate the biomechanical effects of the foot orthoses in the RA patients. Twelve female RA patients with foot pain in walking, all Steinbrocker class II, and 8 healthy women without foot pain were matched for age. Foot pressures and loading forces with and without orthoses were measured using the F-Scan program. The pressure distributions and loading forces were standardized by the body weight and compared, and the effects of the foot orthoses were evaluated. The foot orthoses of RA patients provided higher pressure reduction than those of the control group (3.00 +/- 0.38 g/cm2/BW and 3.29 +/- 0.29 g/cm2/BW respectively, p < 0.001). Similar redistribution of plantar pressures and loading forces were found between two groups but the RA patients had a greater change at the stance phase of gait (p < 0.0001). The foot orthosis produces greater pressure and loading force relief and redistribution in RA patients than in normal subjects.

Adult↗

Apolipoprotein E accelerates the efflux of cholesterol from macrophages: mechanism of xanthoma formation in apolipoprotein E deficiency.

A patient with congenitally deficient apolipoprotein (apo) E showed numerous tuberoerutive, tendon xanthomas and severe atherosclerosis, despite a low LDL concentration. In order to study the mechanism of xanthoma formation observed in apo E deficient patients, we evaluated the effect of VLDL and HDL from the patient on cholesterol ester (CE) accumulation in macrophages. The results showed that there was no difference in CE formation in macrophages among normal VLDL, the patient's VLDL and apo E containing VLDL, which was prepared by incubation of the patient's VLDL with recombinant apo E. On the other hand, apo E containing HDL, which was prepared by incubation of the patient's HDL with recombinant apo E, accelerated cholesterol efflux more effectively than did the patient's HDL and decreased intracellular CE content. Moreover, free apo E accelerated cholesterol efflux from lipid loaded macrophages. These results suggest that macrophages are prevented from transforming into foam cells by their secretion of apo E. This may also explain the marked atherosclerosis and xanthomatosis observed in the patient with apo E-deficiency.

Apolipoproteins E↗

[Evaluation of extraocular muscle enlargement in dysthyroid ophthalmopathy].

PURPOSE: To evaluate the extraocular muscle enlargement in dysthyroid opthalmopathy. METHOD: Extraocular muscle enlargement was assessed by orbital computed tomography (CT) in 573 patients with dysthyroid ophthalmopathy in order to investigate the frequency and exact location of extraocular muscle enlargement and the clinical features of related ocular symptoms in patients with dysthyroid ophthalmopathy. RESULTS AND CONCLUSION: 187 patients (38% of the total) showed evidence of extraocular muscle enlargement on CT images, and this disorder were more frequent in male patients than in female patients. Extraocular muscle enlargement was also more frequently seen in older patients than in younger patients. Enlargement of a single muscle was found in 55% of the 187 patients, with the most frequently affected muscle being the inferior rectus muscle. When multiple muscles were enlarged, the inferior rectus muscle was the most frequently affected, followed by the medial rectus muscle. Of the clinical findings specific to dysthyroid ophthalmopathy examined in the present study, the incidence of exophthaomos, upper lid swelling, superior limbic keratoconjunctivitis, keratitis, diplopia, and dysthyroid optic neuropathy were significantly increased in patients with dysthyroid ophthalmopathy, indicating a close relationship between these findings and the underlying disease, but the incidence of upper lid retraction was not significantly increased.

Adolescent↗

[Transient enlargement and spontaneous regression of interhemispheric cysts--a case report].

We report a 5-year-old male patient with interhemispheric cysts which showed spontaneous reduction in size. The patient was consulted to our hospital at 2 days of life for the evaluation of intracranial cysts found by fetal ultrasonography. Magnetic resonance imaging (MRI) on admission disclosed multiple cysts in the interhemispheric region and agenesis of the corpus callosum. MRI performed later disclosed the association of pachygyria and heterotopia. On follow-up MRIs, the cysts peaked in size at 5 month of age and gradually reduced thereafter. He showed transient hypertonia but had neither neurological deficits nor signs of increased intracranial pressure except transient hypertonia throughout the course. The present case is the first with interhemispheric cysts showing spontaneous reduction in size. While the present case suggested that an interhemispheric cyst dose not necessarily need a surgical treatment, and that it is difficult to determine surgical indication based on clinical manifestations.

Brain Diseases↗

Gradient of nuclear volume changes in breast cancer and its relation to prognosis.

OBJECTIVE: In a study of 112 cases of invasive breast cancer, the prognostic value of the gradient of nuclear volume (NV) changes was examined. STUDY DESIGN: On conventional histologic slides of surgically resected specimens, we studied the nuclear changes from early to advanced. The former was represented by the noninvasive area in the tumor periphery and the latter by the invasive area with true neoplastic stroma. We analyzed the difference in NV between the noninvasive area in the tumor periphery (NVcis) and the invasive area where the nuclei are large (NVlarge), a zone we assessed to have the greatest cancer progression. Based on these measurements, we defined NV gradient index (NVG index) as the ratio of NVlarge to NVcis. RESULTS: The NVG index in cases of cancer death (4.33 +/- 1.70, n = 35) was significantly larger than in relapsing survivors (2.76 +/- 1.31, n = 13, P = .002) and in relapse-free survivors (2.17 +/- 1.60, n = 64, P < .0003). In the group of cancer deaths, the correlation coefficient between NVG index and survival was -0.398 (0 < P < .02). Even in cases of stage I, NVG index in the group of cancer deaths (5.68 +/- 1.4) was significantly larger than in relapsing survivors (2.42 +/- 1.2) or relapse-free survivors (1.74 +/- 0.55). By multivariate analysis, NVG index was independently prognostic for disease-specific survival (P = .0001). CONCLUSION: The NVG index contributes to discrimination between possible survivors and cancer deaths. Though there are exceptions, cases with a small NVG index can be expected to survive for a longer period even after a relapse.

Breast Neoplasms↗

Real-time polymerase chain reaction for quantification of HTLV-1 proviral load: application for analyzing aberrant integration of the proviral DNA in adult T-cell leukemia.

We describe the establishment of a real-time polymerase chain reaction (PCR) assay for the quantitative estimation of human T-cell leukemia virus type 1 (HTLV-1) proviral load using a LightCycler Technology (Roche Diagnostics, Mannheim, Germany) instrument. Proviral DNA level represents a measure of the integrated viral genome in host cells, so we applied this technique to evaluate the tumor burden in adult T-cell leukemia (ATL) patients with aberrant integration patterns of HTLV-1 detected by standard Southern blot hybridization (SBH) analysis. In 14 of our 15 ATL cases with 2 or more bands detected by SBH analysis, the ATL cells were shown to harbor multiple copies of the provirus within 1 ATL cell. This result suggests the usefulness of real-time PCR quantification for the study of the relationship between ATL pathology and HTLV-1-induced pathogenesis.

DNA, Viral↗

[Morphological basis of periodontal nerve endings].

The periodontal ligament, a dense collagenous tissue between tooth and alveolar bone, receives a rich sensory nerve supply, and contains two kinds of sensory receptors; nociceptor and mechanoreceptor. The mechanical stimuli for teeth can evoke various oral reflexes, which facilitate mastication via the periodontal mechanoreceptors. In spite of many reports on the periodontal sensory receptors, recent studies have revealed that the Ruffini endings, categorized as low-threshold slowly adapting type II (SA II) stretch receptors, are primary mechanoreceptors in the periodontal ligament. This paper summarized recent findings on the morphological features and developmental aspects of the periodontal Ruffini endings.

Animals↗

Early onset of hemophagocytic syndrome following allogeneic bone marrow transplantation.

We report a 40-year-old man who presented with acute onset of hemophagocytic syndrome (HPS) after allogeneic bone marrow transplantation (alloBMT) for acute myelogenous leukemia. On day 8 after alloBMT, the patient suddenly manifested high-grade fever, transfusion-resistant severe anemia, and thrombocytopenia. Neither veno-occlusive disease nor thrombotic microangiopathy was documented. The level of ferritin in serum was elevated to 1192 ng/mL. A bone marrow aspiration test on day 16 showed a markedly increased number of activated macrophages showing massive hemophagocytosis. Serum levels of interferon-gamma, soluble interleukin-2 receptor, interleukin-6, tumor necrosis factor-alpha, and macrophage colony-stimulating factor (M-CSF) were elevated. From these findings, we determined his transfusion-resistant cytopenias to be attributable to HPS. No viruses (including cytomegalovirus, Epstein-Barr virus, human herpes-virus-6, parvovirus B19, and adenovirus B11) were detected in serum or urine by polymerase chain reaction amplification. We speculate that in addition to the administration of M-CSF, hypercytokinemia during the early phase post-alloBMT might have contributed to the onset of HPS in this patient. Methylprednisolone pulse therapy was very effective for the treatment of the HPS. This case reveals that HPS could develop after alloBMT, even when engraftment of hematopoietic cells is not confirmed.

Adult↗

[Bacteria isolated from surgical infections and their susceptibilities to antimicrobial agents. Special references to bacteria isolated between April 1997 and March 1998].

The annual multicenter studies on isolated bacteria from infections in general surgery and their antimicrobial susceptibility have been conducted in 19 facilities in Japan since July 1982. This paper describes the results obtained during the period from April 1997 to March 1998. The number of cases investigated as objectives was 215 for one year. A total of 420 strains (170 strains from primary infections and 250 strains from postoperative infections) were isolated from 174 cases (80.9% of total cases). In primary infections, the isolation rate of anaerobic bacteria was higher than in postoperative infections, while in postoperative infections, those of aerobic Gram-positive bacteria and Pseudomonas aeruginosa were higher than in primary infections. Among aerobic Gram-positive bacteria, the isolation rate of Enterococcus faecalis was the highest, followed by Staphylococcus aureus, which was frequently isolated from postoperative infections. Among anaerobic Gram-positive bacteria, Peptostreptococcus spp. and Streptococcus spp. were commonly isolated from both types of infections. Among aerobic Gram-negative bacteria, Escherichia coli was most predominantly isolated from primary infections, followed by P. aeruginosa, Klebsiella pneumoniae in this order, and from postoperative infections, P. aeruginosa was most predominantly isolated, followed by E. coli and K. pneumoniae. Among anaerobic Gram-negative bacteria, Bacteroides fragilis group was the majority of isolates from both types of infections. We found neither vancomycin nor arbekacin resistant strains of S. aureus, and found no vancomycin resistant strains of Enterococcus spp. The susceptibility of P. aeruginosa against carbapenems did not decline in the year 1997, while resistance of B. fragilis group against cephems advanced increasingly.

Anti-Bacterial Agents↗

Development of a new silicone membrane oxygenator for ECMO.

Two types small and efficient ECMO oxygenators were developed utilizing the most up to date hollow fiber technology. Newly silicone hollow fibers possess sufficient mechanical strength while maintaining ultra thin walls of 50 micro meter. Two types of oxygenators were made with this fiber. The fiber length for the type 1 module is 150mm with a priming volume 194 cc (surface area 1.3 m(2)) and type 2 has a fiber length of 100 mm with a 144 cc priming volume (the surface area 0.8 m(2)). The studies were performed at 0.5, 1.0 and 2.0 L/min of blood flow and these oxygenators demonstrated. O(2) gas transfer rate of 69+/-4 ml/min/L for type 1 and 68+/-6 ml/min/L for type 2. The CO(2) gas transfer rate was 25+/-2 ml/min/L for type 1 and 32+/-2 ml/min/L for type 2. These results demonstrate type 2 oxygenator has similar gas exchange capabilities to those of Kolobows' oxygenator which has about 2.0 times larger surface area. Additionally, comparative hemolysis tests were preformed with this new oxygenator and the Kolbow. The NIH value was 0.006 (g/100 L) for the type 1 oxygenator and 0.01 (g/100 L) for the Kolbow oxygenator. These results suggested that this ECMO oxygenator had sufficient gas exchange performance in spite of being smaller and induced minimal blood damage.

Equipment Design↗